I have an intex kristal clear sand filter for my 16 foot round intex ultra frame pool. What is neutral used for on the filter or do you use it ?

SOURCE: Problems with Intex Krystal Clear Model 635 Pool Filter Pump 1500

No, the pump should not be noisy. It sounds like you have picked up a foreign object in the pump housing. you may have to pull the face off to determine. OR the pump/motor is indeed defective and should be returned.

SOURCE: my pool sand filter pump isnt filtering the water

could possbly be a bad gasket on the vari-flow valve. When is the last time you backwashed?

SOURCE: How to change sand in Hayward S-200 Sand filter

hayward S-180 filter takes 150lbs, S-210 takes 200lbs not familur with the S-200. To change sand you have to remove the vari flow valve on top. You can either unplumb the filter and roll it over on its side and try washing the sand out or try scooping it out upright. Whatever you do dont damage the laterals on the bottom of the filter. When refilling with sand you want to make sure all the laterals are undamaged and in the down position. I always fill the filter half full of water to keep the sand from damaging the laterals while re-filling the filter with sand. Make sure you use pool filter sand and not play sand!

SOURCE: what is the normal psi on a haward sand filter

i was told that between 9 to 12 psi is normal on all pool pumps.

SOURCE: I have a 15x 42" intex metal frame pool an i also

Most likely you are not. The manual is very conservative!!! I have a 14000 gallon pool and I run my intex salt system during the summer at 10 to 12 hrs pump and 8 to 10 hrs chlorination in between those 12 hrs and my pool stays very clear. But..... If you don't clean the unit and let it alarm for low flow, low salt or not run the unit log enough, you WILL HAVE GREEN WATER!!!
Hope this helps, If it does, please rate the tip!